复合材料加筋板大开口结构拉伸与修理性能

Tensile Performance and Repair Performance of Composites Stiffened Panel With Large Cutout

复合材料加筋板大开口结构在承受轴向拉伸载荷时主要的应力集中部位是大开口的边缘处。根据试验过程中的观测和破坏模式的成像记录,结构损伤从这一点开始,沿横向偏加载方向扩展,直至完全拉断。使用商用有限元分析软件ABAQUS构建的有限元模型的计算结果显示孔边的应变在破坏发生前呈线性增加,在破坏发生的时刻急剧增大,与试验测得应变一致。为研究复合材料加筋板大开口结构的修理性能,建立了预置损伤板以及相应的2类修理方案(机械连接修理板、胶接修理板)的有限元模型。预制损伤是位于加筋板横向轴线上、孔边蒙皮开间中央位置的圆形小孔,以此模拟蒙皮穿透损伤。预置的损伤对加筋板的刚度影响不大,使其强度下降0.16%。机械连接采用金属补片,修理后的加筋板强度比完好板提高0.32%。胶接修理采用单面挖补修理,修理后的加筋板强度比完好板提高0.31%。

Composite stiffened panel structure with large cutout under the axial tensile load, has a serious stress concentration at the edge of the cutout generally. According to the observing during the test and recording of failure mode alter it, structural damage starts from this edge, expands along the transverse of panel intending load- ing direction a little, until structure completely tails. Using commercial finite element analysis software ABAQUS, finite element models are constructed and calculations show that strain at the edge of cutout increases linearly before destruction occurrs. When the destruction occurs, the strain get a sharp increase, what is consistent with the experimental strain result. To study the performance of repaired composite stiffened panel with large cutout, three kinds of models are built, including panel with damage and the panels with corresponding types of repair program： bolted repair panel and bonded repair panel. Precast dam- age locats on the horizontal axis, near the cutout edge and in skin bay, as a circular hole, in order to simulate tile skin penetrating injury. Pre-damage of stifl＇ened panel has little effect on stiffness, but stiffened panel＇s strength declines 0.16 percent. Panel repaired by bolt using metal patch, has a 0.32 percent increasing in intensity than intact plate. Bond repaired panel has a 0.31 percent increasing in inten- sity than intact plate.